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Add G.726-32kbps Codec Transcoder (Tested with Cisco ATA-186) 

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@2239 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Mark Spencer 2004-02-25 04:10:32 +00:00
parent 96abbad91d
commit ff976ce055
5 changed files with 1000 additions and 2 deletions
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3
codecs/Makefile
View File

@ -34,7 +34,8 @@ LIBSPEEX+=-lspeex -lm
LIBILBC=ilbc/libilbc.a
CODECS+=$(MODG723) $(MODSPEEX) $(MODILBC) codec_gsm.so codec_lpc10.so \
codec_adpcm.so codec_ulaw.so codec_alaw.so codec_a_mu.so
codec_adpcm.so codec_ulaw.so codec_alaw.so codec_a_mu.so \
codec_g726.so
all: depend $(CODECS)

927
codecs/codec_g726.c Executable file
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@ -0,0 +1,927 @@
/* codec_g726.c - translate between signed linear and ITU G.726-32kbps
*
* Asterisk -- A telephony toolkit for Linux.
*
* Based on frompcm.c and topcm.c from the Emiliano MIPL browser/
* interpreter. See http://www.bsdtelephony.com.mx
*
* Copyright (c) 2004, Digium
*
* Mark Spencer <markster@digium.com>
*
* This program is free software, distributed under the terms of
* the GNU General Public License
*/
#include <asterisk/lock.h>
#include <asterisk/logger.h>
#include <asterisk/module.h>
#include <asterisk/translate.h>
#include <asterisk/channel.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define BUFFER_SIZE 8096 /* size for the translation buffers */
#define BUF_SHIFT 5
static ast_mutex_t localuser_lock = AST_MUTEX_INITIALIZER;
static int localusecnt = 0;
static char *tdesc = "ITU G.726-32kbps G726 Transcoder";
/* Sample frame data */
#include "slin_g726_ex.h"
#include "g726_slin_ex.h"
/*
* The following is the definition of the state structure
* used by the G.721/G.723 encoder and decoder to preserve their internal
* state between successive calls. The meanings of the majority
* of the state structure fields are explained in detail in the
* CCITT Recommendation G.721. The field names are essentially indentical
* to variable names in the bit level description of the coding algorithm
* included in this Recommendation.
*/
struct g726_state {
long yl; /* Locked or steady state step size multiplier. */
short yu; /* Unlocked or non-steady state step size multiplier. */
short dms; /* Short term energy estimate. */
short dml; /* Long term energy estimate. */
short ap; /* Linear weighting coefficient of 'yl' and 'yu'. */
short a[2]; /* Coefficients of pole portion of prediction filter. */
short b[6]; /* Coefficients of zero portion of prediction filter. */
short pk[2]; /*
* Signs of previous two samples of a partially
* reconstructed signal.
*/
short dq[6]; /*
* Previous 6 samples of the quantized difference
* signal represented in an internal floating point
* format.
*/
short sr[2]; /*
* Previous 2 samples of the quantized difference
* signal represented in an internal floating point
* format.
*/
char td; /* delayed tone detect, new in 1988 version */
};
static short qtab_721[7] = {-124, 80, 178, 246, 300, 349, 400};
/*
* Maps G.721 code word to reconstructed scale factor normalized log
* magnitude values.
*/
static short _dqlntab[16] = {-2048, 4, 135, 213, 273, 323, 373, 425,
425, 373, 323, 273, 213, 135, 4, -2048};
/* Maps G.721 code word to log of scale factor multiplier. */
static short _witab[16] = {-12, 18, 41, 64, 112, 198, 355, 1122,
1122, 355, 198, 112, 64, 41, 18, -12};
/*
* Maps G.721 code words to a set of values whose long and short
* term averages are computed and then compared to give an indication
* how stationary (steady state) the signal is.
*/
static short _fitab[16] = {0, 0, 0, 0x200, 0x200, 0x200, 0x600, 0xE00,
0xE00, 0x600, 0x200, 0x200, 0x200, 0, 0, 0};
static short power2[15] = {1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80,
0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000};
/*
* quan()
*
* quantizes the input val against the table of size short integers.
* It returns i if table[i - 1] <= val < table[i].
*
* Using linear search for simple coding.
*/
static int quan(int val, short *table, int size)
{
int i;
for (i = 0; i < size; i++)
if (val < *table++)
break;
return (i);
}
/*
* fmult()
*
* returns the integer product of the 14-bit integer "an" and
* "floating point" representation (4-bit exponent, 6-bit mantessa) "srn".
*/
static int fmult(int an, int srn)
{
short anmag, anexp, anmant;
short wanexp, wanmant;
short retval;
anmag = (an > 0) ? an : ((-an) & 0x1FFF);
anexp = quan(anmag, power2, 15) - 6;
anmant = (anmag == 0) ? 32 :
(anexp >= 0) ? anmag >> anexp : anmag << -anexp;
wanexp = anexp + ((srn >> 6) & 0xF) - 13;
wanmant = (anmant * (srn & 077) + 0x30) >> 4;
retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) :
(wanmant >> -wanexp);
return (((an ^ srn) < 0) ? -retval : retval);
}
/*
* g72x_init_state()
*
* This routine initializes and/or resets the g726_state structure
* pointed to by 'state_ptr'.
* All the initial state values are specified in the CCITT G.721 document.
*/
static void g726_init_state(struct g726_state *state_ptr)
{
int cnta;
state_ptr->yl = 34816;
state_ptr->yu = 544;
state_ptr->dms = 0;
state_ptr->dml = 0;
state_ptr->ap = 0;
for (cnta = 0; cnta < 2; cnta++) {
state_ptr->a[cnta] = 0;
state_ptr->pk[cnta] = 0;
state_ptr->sr[cnta] = 32;
}
for (cnta = 0; cnta < 6; cnta++) {
state_ptr->b[cnta] = 0;
state_ptr->dq[cnta] = 32;
}
state_ptr->td = 0;
}
/*
* predictor_zero()
*
* computes the estimated signal from 6-zero predictor.
*
*/
static int predictor_zero(struct g726_state *state_ptr)
{
int i;
int sezi;
sezi = fmult(state_ptr->b[0] >> 2, state_ptr->dq[0]);
for (i = 1; i < 6; i++) /* ACCUM */
sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]);
return (sezi);
}
/*
* predictor_pole()
*
* computes the estimated signal from 2-pole predictor.
*
*/
static int predictor_pole(struct g726_state *state_ptr)
{
return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) +
fmult(state_ptr->a[0] >> 2, state_ptr->sr[0]));
}
/*
* step_size()
*
* computes the quantization step size of the adaptive quantizer.
*
*/
static int step_size(struct g726_state *state_ptr)
{
int y;
int dif;
int al;
if (state_ptr->ap >= 256)
return (state_ptr->yu);
else {
y = state_ptr->yl >> 6;
dif = state_ptr->yu - y;
al = state_ptr->ap >> 2;
if (dif > 0)
y += (dif * al) >> 6;
else if (dif < 0)
y += (dif * al + 0x3F) >> 6;
return (y);
}
}
/*
* quantize()
*
* Given a raw sample, 'd', of the difference signal and a
* quantization step size scale factor, 'y', this routine returns the
* ADPCM codeword to which that sample gets quantized. The step
* size scale factor division operation is done in the log base 2 domain
* as a subtraction.
*/
static int quantize(
int d, /* Raw difference signal sample */
int y, /* Step size multiplier */
short *table, /* quantization table */
int size) /* table size of short integers */
{
short dqm; /* Magnitude of 'd' */
short exp; /* Integer part of base 2 log of 'd' */
short mant; /* Fractional part of base 2 log */
short dl; /* Log of magnitude of 'd' */
short dln; /* Step size scale factor normalized log */
int i;
/*
* LOG
*
* Compute base 2 log of 'd', and store in 'dl'.
*/
dqm = abs(d);
exp = quan(dqm >> 1, power2, 15);
mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */
dl = (exp << 7) + mant;
/*
* SUBTB
*
* "Divide" by step size multiplier.
*/
dln = dl - (y >> 2);
/*
* QUAN
*
* Obtain codword i for 'd'.
*/
i = quan(dln, table, size);
if (d < 0) /* take 1's complement of i */
return ((size << 1) + 1 - i);
else if (i == 0) /* take 1's complement of 0 */
return ((size << 1) + 1); /* new in 1988 */
else
return (i);
}
/*
* reconstruct()
*
* Returns reconstructed difference signal 'dq' obtained from
* codeword 'i' and quantization step size scale factor 'y'.
* Multiplication is performed in log base 2 domain as addition.
*/
static int reconstruct(
int sign, /* 0 for non-negative value */
int dqln, /* G.72x codeword */
int y) /* Step size multiplier */
{
short dql; /* Log of 'dq' magnitude */
short dex; /* Integer part of log */
short dqt;
short dq; /* Reconstructed difference signal sample */
dql = dqln + (y >> 2); /* ADDA */
if (dql < 0) {
return ((sign) ? -0x8000 : 0);
} else { /* ANTILOG */
dex = (dql >> 7) & 15;
dqt = 128 + (dql & 127);
dq = (dqt << 7) >> (14 - dex);
return ((sign) ? (dq - 0x8000) : dq);
}
}
/*
* update()
*
* updates the state variables for each output code
*/
static void update(
int code_size, /* distinguish 723_40 with others */
int y, /* quantizer step size */
int wi, /* scale factor multiplier */
int fi, /* for long/short term energies */
int dq, /* quantized prediction difference */
int sr, /* reconstructed signal */
int dqsez, /* difference from 2-pole predictor */
struct g726_state *state_ptr) /* coder state pointer */
{
int cnt;
short mag, exp; /* Adaptive predictor, FLOAT A */
short a2p=0; /* LIMC */
short a1ul; /* UPA1 */
short pks1; /* UPA2 */
short fa1;
char tr; /* tone/transition detector */
short ylint, thr2, dqthr;
short ylfrac, thr1;
short pk0;
pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */
mag = dq & 0x7FFF; /* prediction difference magnitude */
/* TRANS */
ylint = state_ptr->yl >> 15; /* exponent part of yl */
ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */
thr1 = (32 + ylfrac) << ylint; /* threshold */
thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */
dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */
if (state_ptr->td == 0) /* signal supposed voice */
tr = 0;
else if (mag <= dqthr) /* supposed data, but small mag */
tr = 0; /* treated as voice */
else /* signal is data (modem) */
tr = 1;
/*
* Quantizer scale factor adaptation.
*/
/* FUNCTW & FILTD & DELAY */
/* update non-steady state step size multiplier */
state_ptr->yu = y + ((wi - y) >> 5);
/* LIMB */
if (state_ptr->yu < 544) /* 544 <= yu <= 5120 */
state_ptr->yu = 544;
else if (state_ptr->yu > 5120)
state_ptr->yu = 5120;
/* FILTE & DELAY */
/* update steady state step size multiplier */
state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6);
/*
* Adaptive predictor coefficients.
*/
if (tr == 1) { /* reset a's and b's for modem signal */
state_ptr->a[0] = 0;
state_ptr->a[1] = 0;
state_ptr->b[0] = 0;
state_ptr->b[1] = 0;
state_ptr->b[2] = 0;
state_ptr->b[3] = 0;
state_ptr->b[4] = 0;
state_ptr->b[5] = 0;
} else { /* update a's and b's */
pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */
/* update predictor pole a[1] */
a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7);
if (dqsez != 0) {
fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0];
if (fa1 < -8191) /* a2p = function of fa1 */
a2p -= 0x100;
else if (fa1 > 8191)
a2p += 0xFF;
else
a2p += fa1 >> 5;
if (pk0 ^ state_ptr->pk[1])
/* LIMC */
if (a2p <= -12160)
a2p = -12288;
else if (a2p >= 12416)
a2p = 12288;
else
a2p -= 0x80;
else if (a2p <= -12416)
a2p = -12288;
else if (a2p >= 12160)
a2p = 12288;
else
a2p += 0x80;
}
/* TRIGB & DELAY */
state_ptr->a[1] = a2p;
/* UPA1 */
/* update predictor pole a[0] */
state_ptr->a[0] -= state_ptr->a[0] >> 8;
if (dqsez != 0) {
if (pks1 == 0)
state_ptr->a[0] += 192;
else
state_ptr->a[0] -= 192;
}
/* LIMD */
a1ul = 15360 - a2p;
if (state_ptr->a[0] < -a1ul)
state_ptr->a[0] = -a1ul;
else if (state_ptr->a[0] > a1ul)
state_ptr->a[0] = a1ul;
/* UPB : update predictor zeros b[6] */
for (cnt = 0; cnt < 6; cnt++) {
if (code_size == 5) /* for 40Kbps G.723 */
state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9;
else /* for G.721 and 24Kbps G.723 */
state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8;
if (dq & 0x7FFF) { /* XOR */
if ((dq ^ state_ptr->dq[cnt]) >= 0)
state_ptr->b[cnt] += 128;
else
state_ptr->b[cnt] -= 128;
}
}
}
for (cnt = 5; cnt > 0; cnt--)
state_ptr->dq[cnt] = state_ptr->dq[cnt-1];
/* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */
if (mag == 0) {
state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0xFC20;
} else {
exp = quan(mag, power2, 15);
state_ptr->dq[0] = (dq >= 0) ?
(exp << 6) + ((mag << 6) >> exp) :
(exp << 6) + ((mag << 6) >> exp) - 0x400;
}
state_ptr->sr[1] = state_ptr->sr[0];
/* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */
if (sr == 0) {
state_ptr->sr[0] = 0x20;
} else if (sr > 0) {
exp = quan(sr, power2, 15);
state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp);
} else if (sr > -32768) {
mag = -sr;
exp = quan(mag, power2, 15);
state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400;
} else
state_ptr->sr[0] = 0xFC20;
/* DELAY A */
state_ptr->pk[1] = state_ptr->pk[0];
state_ptr->pk[0] = pk0;
/* TONE */
if (tr == 1) /* this sample has been treated as data */
state_ptr->td = 0; /* next one will be treated as voice */
else if (a2p < -11776) /* small sample-to-sample correlation */
state_ptr->td = 1; /* signal may be data */
else /* signal is voice */
state_ptr->td = 0;
/*
* Adaptation speed control.
*/
state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */
state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */
if (tr == 1)
state_ptr->ap = 256;
else if (y < 1536) /* SUBTC */
state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
else if (state_ptr->td == 1)
state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
else if (abs((state_ptr->dms << 2) - state_ptr->dml) >=
(state_ptr->dml >> 3))
state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
else
state_ptr->ap += (-state_ptr->ap) >> 4;
}
/*
* g726_decode()
*
* Description:
*
* Decodes a 4-bit code of G.726-32 encoded data of i and
* returns the resulting linear PCM, A-law or u-law value.
* return -1 for unknown out_coding value.
*/
static int g726_decode(int i, struct g726_state *state_ptr)
{
short sezi, sei, sez, se; /* ACCUM */
short y; /* MIX */
short sr; /* ADDB */
short dq;
short dqsez;
i &= 0x0f; /* mask to get proper bits */
sezi = predictor_zero(state_ptr);
sez = sezi >> 1;
sei = sezi + predictor_pole(state_ptr);
se = sei >> 1; /* se = estimated signal */
y = step_size(state_ptr); /* dynamic quantizer step size */
dq = reconstruct(i & 0x08, _dqlntab[i], y); /* quantized diff. */
sr = (dq < 0) ? (se - (dq & 0x3FFF)) : se + dq; /* reconst. signal */
dqsez = sr - se + sez; /* pole prediction diff. */
update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr);
return (sr << 2); /* sr was 14-bit dynamic range */
}
/*
* g726_encode()
*
* Encodes the input vale of linear PCM, A-law or u-law data sl and returns
* the resulting code. -1 is returned for unknown input coding value.
*/
static int g726_encode(int sl, struct g726_state *state_ptr)
{
short sezi, se, sez; /* ACCUM */
short d; /* SUBTA */
short sr; /* ADDB */
short y; /* MIX */
short dqsez; /* ADDC */
short dq, i;
sl >>= 2; /* 14-bit dynamic range */
sezi = predictor_zero(state_ptr);
sez = sezi >> 1;
se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */
d = sl - se; /* estimation difference */
/* quantize the prediction difference */
y = step_size(state_ptr); /* quantizer step size */
i = quantize(d, y, qtab_721, 7); /* i = G726 code */
dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized est diff */
sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */
dqsez = sr + sez - se; /* pole prediction diff. */
update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr);
return (i);
}
/*
* Private workspace for translating signed linear signals to G726.
*/
struct g726_encoder_pvt
{
struct ast_frame f;
char offset[AST_FRIENDLY_OFFSET]; /* Space to build offset */
unsigned char outbuf[BUFFER_SIZE]; /* Encoded G726, two nibbles to a word */
unsigned char next_flag;
struct g726_state g726;
int tail;
};
/*
* Private workspace for translating G726 signals to signed linear.
*/
struct g726_decoder_pvt
{
struct ast_frame f;
char offset[AST_FRIENDLY_OFFSET]; /* Space to build offset */
short outbuf[BUFFER_SIZE]; /* Decoded signed linear values */
struct g726_state g726;
int tail;
};
/*
* G726ToLin_New
* Create a new instance of g726_decoder_pvt.
*
* Results:
* Returns a pointer to the new instance.
*
* Side effects:
* None.
*/
static struct ast_translator_pvt *
g726tolin_new (void)
{
struct g726_decoder_pvt *tmp;
tmp = malloc (sizeof (struct g726_decoder_pvt));
if (tmp)
{
memset(tmp, 0, sizeof(*tmp));
tmp->tail = 0;
localusecnt++;
g726_init_state(&tmp->g726);
ast_update_use_count ();
}
return (struct ast_translator_pvt *) tmp;
}
/*
* LinToG726_New
* Create a new instance of g726_encoder_pvt.
*
* Results:
* Returns a pointer to the new instance.
*
* Side effects:
* None.
*/
static struct ast_translator_pvt *
lintog726_new (void)
{
struct g726_encoder_pvt *tmp;
tmp = malloc (sizeof (struct g726_encoder_pvt));
if (tmp)
{
memset(tmp, 0, sizeof(*tmp));
localusecnt++;
tmp->tail = 0;
g726_init_state(&tmp->g726);
ast_update_use_count ();
}
return (struct ast_translator_pvt *) tmp;
}
/*
* G726ToLin_FrameIn
* Fill an input buffer with packed 4-bit G726 values if there is room
* left.
*
* Results:
* Foo
*
* Side effects:
* tmp->tail is the number of packed values in the buffer.
*/
static int
g726tolin_framein (struct ast_translator_pvt *pvt, struct ast_frame *f)
{
struct g726_decoder_pvt *tmp = (struct g726_decoder_pvt *) pvt;
unsigned char *b;
int x;
b = f->data;
for (x=0;x<f->datalen;x++) {
if (tmp->tail >= BUFFER_SIZE) {
ast_log(LOG_WARNING, "Out of buffer space!\n");
return -1;
}
tmp->outbuf[tmp->tail++] = g726_decode((b[x] >> 4) & 0xf, &tmp->g726);
if (tmp->tail >= BUFFER_SIZE) {
ast_log(LOG_WARNING, "Out of buffer space!\n");
return -1;
}
tmp->outbuf[tmp->tail++] = g726_decode(b[x] & 0x0f, &tmp->g726);
}
return 0;
}
/*
* G726ToLin_FrameOut
* Convert 4-bit G726 encoded signals to 16-bit signed linear.
*
* Results:
* Converted signals are placed in tmp->f.data, tmp->f.datalen
* and tmp->f.samples are calculated.
*
* Side effects:
* None.
*/
static struct ast_frame *
g726tolin_frameout (struct ast_translator_pvt *pvt)
{
struct g726_decoder_pvt *tmp = (struct g726_decoder_pvt *) pvt;
if (!tmp->tail)
return NULL;
tmp->f.frametype = AST_FRAME_VOICE;
tmp->f.subclass = AST_FORMAT_SLINEAR;
tmp->f.datalen = tmp->tail * 2;
tmp->f.samples = tmp->tail;
tmp->f.mallocd = 0;
tmp->f.offset = AST_FRIENDLY_OFFSET;
tmp->f.src = __PRETTY_FUNCTION__;
tmp->f.data = tmp->outbuf;
tmp->tail = 0;
return &tmp->f;
}
/*
* LinToG726_FrameIn
* Fill an input buffer with 16-bit signed linear PCM values.
*
* Results:
* None.
*
* Side effects:
* tmp->tail is number of signal values in the input buffer.
*/
static int
lintog726_framein (struct ast_translator_pvt *pvt, struct ast_frame *f)
{
struct g726_encoder_pvt *tmp = (struct g726_encoder_pvt *) pvt;
short *s = f->data;
int samples = f->datalen / 2;
int x;
for (x=0;x<samples;x++) {
if (tmp->next_flag & 0x80) {
if (tmp->tail >= BUFFER_SIZE) {
ast_log(LOG_WARNING, "Out of buffer space\n");
return -1;
}
tmp->outbuf[tmp->tail++] = ((tmp->next_flag & 0xf)<< 4) | g726_encode(s[x], &tmp->g726);
tmp->next_flag = 0;
} else {
tmp->next_flag = 0x80 | g726_encode(s[x], &tmp->g726);
}
}
return 0;
}
/*
* LinToG726_FrameOut
* Convert a buffer of raw 16-bit signed linear PCM to a buffer
* of 4-bit G726 packed two to a byte (Big Endian).
*
* Results:
* Foo
*
* Side effects:
* Leftover inbuf data gets packed, tail gets updated.
*/
static struct ast_frame *
lintog726_frameout (struct ast_translator_pvt *pvt)
{
struct g726_encoder_pvt *tmp = (struct g726_encoder_pvt *) pvt;
if (!tmp->tail)
return NULL;
tmp->f.frametype = AST_FRAME_VOICE;
tmp->f.subclass = AST_FORMAT_G726;
tmp->f.samples = tmp->tail * 2;
tmp->f.mallocd = 0;
tmp->f.offset = AST_FRIENDLY_OFFSET;
tmp->f.src = __PRETTY_FUNCTION__;
tmp->f.data = tmp->outbuf;
tmp->f.datalen = tmp->tail;
tmp->tail = 0;
return &tmp->f;
}
/*
* G726ToLin_Sample
*/
static struct ast_frame *
g726tolin_sample (void)
{
static struct ast_frame f;
f.frametype = AST_FRAME_VOICE;
f.subclass = AST_FORMAT_G726;
f.datalen = sizeof (g726_slin_ex);
f.samples = sizeof(g726_slin_ex) * 2;
f.mallocd = 0;
f.offset = 0;
f.src = __PRETTY_FUNCTION__;
f.data = g726_slin_ex;
return &f;
}
/*
* LinToG726_Sample
*/
static struct ast_frame *
lintog726_sample (void)
{
static struct ast_frame f;
f.frametype = AST_FRAME_VOICE;
f.subclass = AST_FORMAT_SLINEAR;
f.datalen = sizeof (slin_g726_ex);
/* Assume 8000 Hz */
f.samples = sizeof (slin_g726_ex) / 2;
f.mallocd = 0;
f.offset = 0;
f.src = __PRETTY_FUNCTION__;
f.data = slin_g726_ex;
return &f;
}
/*
* G726_Destroy
* Destroys a private workspace.
*
* Results:
* It's gone!
*
* Side effects:
* None.
*/
static void
g726_destroy (struct ast_translator_pvt *pvt)
{
free (pvt);
localusecnt--;
ast_update_use_count ();
}
/*
* The complete translator for G726ToLin.
*/
static struct ast_translator g726tolin = {
"g726tolin",
AST_FORMAT_G726,
AST_FORMAT_SLINEAR,
g726tolin_new,
g726tolin_framein,
g726tolin_frameout,
g726_destroy,
/* NULL */
g726tolin_sample
};
/*
* The complete translator for LinToG726.
*/
static struct ast_translator lintog726 = {
"lintog726",
AST_FORMAT_SLINEAR,
AST_FORMAT_G726,
lintog726_new,
lintog726_framein,
lintog726_frameout,
g726_destroy,
/* NULL */
lintog726_sample
};
int
unload_module (void)
{
int res;
ast_mutex_lock (&localuser_lock);
res = ast_unregister_translator (&lintog726);
if (!res)
res = ast_unregister_translator (&g726tolin);
if (localusecnt)
res = -1;
ast_mutex_unlock (&localuser_lock);
return res;
}
int
load_module (void)
{
int res;
res = ast_register_translator (&g726tolin);
if (!res)
res = ast_register_translator (&lintog726);
else
ast_unregister_translator (&g726tolin);
return res;
}
/*
* Return a description of this module.
*/
char *
description (void)
{
return tdesc;
}
int
usecount (void)
{
int res;
STANDARD_USECOUNT (res);
return res;
}
char *
key ()
{
return ASTERISK_GPL_KEY;
}

25
codecs/g726_slin_ex.h Executable file
View File

@ -0,0 +1,25 @@
/*
* adpcm_slin_ex.h --
*
* 4-bit G.726 data, 20 milliseconds worth at 8 kHz.
*
* Source: g726.example
*
* Copyright (C) 2001, Linux Support Services, Inc.
*
* Distributed under the terms of the GNU General Public License
*
*/
static unsigned char g726_slin_ex[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

25
codecs/slin_g726_ex.h Executable file
View File

@ -0,0 +1,25 @@
/*
* slin_adpcm_ex.h --
*
* Signed 16-bit audio data, 10 milliseconds worth at 8 kHz.
*
* Source: g726.example
*
* Copyright (C) 2001, Linux Support Services, Inc.
*
* Distributed under the terms of the GNU General Public License
*
*/
static signed short slin_g726_ex[] = {
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000
};

22
rtp.c
View File

@ -468,6 +468,7 @@ struct ast_frame *ast_rtp_read(struct ast_rtp *rtp)
rtp->f.samples = 240 * (rtp->f.datalen / 50);
break;
case AST_FORMAT_ADPCM:
case AST_FORMAT_G726:
rtp->f.samples = rtp->f.datalen * 2;
break;
case AST_FORMAT_G729A:
@ -912,7 +913,13 @@ static int ast_rtp_raw_write(struct ast_rtp *rtp, struct ast_frame *f, int codec
case AST_FORMAT_ALAW:
/* If we're within +/- 20ms from when where we
predict we should be, use that */
pred = rtp->lastts + f->datalen;
pred = rtp->lastts + f->datalen * 2;
break;
case AST_FORMAT_ADPCM:
case AST_FORMAT_G726:
/* If we're within +/- 20ms from when where we
predict we should be, use that */
pred = rtp->lastts + f->datalen * 2;
break;
case AST_FORMAT_G729A:
pred = rtp->lastts + f->datalen * 8;
@ -1025,6 +1032,19 @@ int ast_rtp_write(struct ast_rtp *rtp, struct ast_frame *_f)
}
ast_smoother_feed(rtp->smoother, _f);
while((f = ast_smoother_read(rtp->smoother)))
ast_rtp_raw_write(rtp, f, codec);
break;
case AST_FORMAT_G726:
if (!rtp->smoother) {
rtp->smoother = ast_smoother_new(80);
}
if (!rtp->smoother) {
ast_log(LOG_WARNING, "Unable to create smoother :(\n");
return -1;
}
ast_smoother_feed(rtp->smoother, _f);
while((f = ast_smoother_read(rtp->smoother)))
ast_rtp_raw_write(rtp, f, codec);
break;